I've been asked towards last before, and I rarely care -- one choice is, more often than not, the same as any other to my taste. Admittedly, that's a very personal thing. I personally don't mind too much (and I'm a great lover of fine dining...).
I'd say that more than half the time this has happened has also been a BRE (bottle-receiving event).
If you really do care what you eat, or you have allergies, and you don't special order a meal then it's worth mentioning something to the F/A upon boarding. Or special order, though that's tougher nowadays.
Regardless, just don't be one of those people that we've all sat next to who give the F/As a hard time. Yes, UA should probably board more meals in the premium cabins to accomodate taste (but there are obvious economics to that). But it isn't the fault of the cabin crew...
------------------
More Room Throughout Coach: the Website of Free Miles and Free Markets